The great market penetration of mobile communication devices in most parts of the world has attracted many industries to provide services by means of mobile radio communications systems. One example is the banking industry, where some banks offer their customers the possibility of receiving information via the Short Message Service (SMS). In the banking industry, as well as in other industries handling information which may be sensitive, privacy and secrecy of information is often of high concern. Although highly convenient, the transmission of information via SMS is generally not entirely secure. Many supporters of SMS based services claim that while SMS banking is not as secure as other conventional banking channels, SMS banking is not intended to be used for very high-risk transactions. However, there is still a desire to improve the security of the delivery of SMS banking and other services utilizing mobile radio communications systems.